Let optimism be your guiding light

As a Nobel Laureate and founder of the AGA company, Gustaf Dalén is probably one of Chalmer’s most famous former students. His invention, the Sun valve, for which he won the Nobel prize 1912, is now on display at Gothenburg Physics Centre, as a reminder of, not only his achievements, but also the optimistic spirit that made them possible.

Kerstin Keen, Peter Keen, Jan-Olof Yxell, Carl Fredrik Ebeling, Melina van Meer and Göran Dalén at the inauguration of the Sun valve at Gothenburg Physics Centre.

— My grandfather would have been delighted. He was very fond of Chalmers and the environment of scientific dialogue he found here, says Peter Keen, one of Gustaf Daléns grandchildren and himself a former Chalmerist, who attended the inauguration of the Sun valve at the Origo-building, Thursday February 19, 2015.

The Sun valve, or the Dalén light as it came to be known, was used in lighthouses all over the world and became a success because it allowed the light to automatically turn on and off and to operate only at night - saving a lot of fuel, but also putting many lighthouse keepers out of work in the early twentieth century.

The construction is based on four metal rods - one blackened in the middle and three polished surrounding it. As the dark rod is able to absorb more heat than the polished ones, its slight expansion in daylight enables it to cut the gas supply of the lighthouse. As the sun sets the central rod cools down, becomes the same size as the polished rods and opens the gas supply that lights the fire.

The Sun valve now in display at Gothenburg Physics Centre, was once placed in the archipelago of Stockholm and was saved from destruction, when being replaced by electric light, by lighthouse enthusiast Carl Fredrik Ebeling.

— It really didn’t need much restoration. The Sun valves just run and run and run for eternity, says Ebeling, who was also the one who contacted Chalmers and donated the piece.

However genius, the Sun valve and other of Gustaf Dalén’s inventions are really the result of his persistent refusal to give up. Göran Dalén, another of Gustaf’s grandchildren, took the opportunity at the inauguration to speak about one of his grandfather’s strongest traits – his optimism. After loosing his eyesight in an acetylene explosion in 1912 (the same year he was awarded the Nobel prize) and twice loosing his fortune in the nineteen-twenties and thirties, he ordered a large number of pins with the words Be optimistic. As well as placing the pins on anyone with a negative attitude he always wore the message on the lapel of his own coat as a reminder that everything is possible.  

Text and photo: Karin Weijdegård

Published: Mon 23 Feb 2015. Modified: Wed 25 Feb 2015